A new Swedish study has reported that modest intake of alcohol after a diagnosis of breast cancer does not increase the risk of breast-cancer specific death and reduces all-cause mortality. Alcohol has been associated with increased risk of breast cancer in numerous population studies. However, there is less data concerning the relationship between drinking alcohol and survival after a breast cancer diagnosis. The study included 3,146 women with invasive breast cancer in the Swedish Mammography Cohort. A food frequency questionnaire was used to estimate alcohol intake. A total of 860 deaths occurred in the study population between 1987 and 2008, of which 385 were breast cancer-specific.

Alcohol intake did not appear to be associated with breast cancer-specific survival. Women who consumed at least 10 g of alcohol per day (corresponding to approximately 0.75 to 1 drinks) had 1.36 times the risk of death from death cancer as non-drinkers, but this result was not statistically significant. On the other hand, a significant inverse relation was found between alcohol and non-breast cancer deaths (often from cardiovascular disease in this population). Women who consumed 3.4 to 9.9 g per day of alcohol had a 33% lower risk of death compared to non-drinkers. The authors conclude that alcohol consumption up to approximately one small drink per day does not negatively impact breast cancer-specific survival and a half drink per day is associated with a decreased risk of mortality from other causes.

Alcohol should not be consumed under some circumstances

The study results suggest that a small amount of alcohol is not harmful for breast cancer survivors. However, survivors should take into account the following before deciding how much, if any, alcohol to drink:

  • A prospective California study concluded that consuming three to four alcoholic drinks or more per week after a breast cancer diagnosis may increase risk of breast cancer recurrence, particularly among postmenopausal and overweight or obese women.
  • Consuming alcohol interferes with the effectiveness of treatment with tamoxifen.
  • Several drinks consumed over a short period of time is more potentially harmful than the same amount of alcohol consumed over a period of days.

Note that while moderate alcohol consumption appears to reduce risk of cardiovascular disease, it should not be consumed by women with heart damage caused by radiotherapy or chemotherapy.